[Interfaces] Migrate away from PointerUnion::{is,get} (NFC)#120845

kazutakahirata merged 1 commit intollvm:mainllvm/llvm-project:mainfrom

kazutakahirata:cleanup_001_PointerUnion_mlir_Interfaceskazutakahirata/llvm-project:cleanup_001_PointerUnion_mlir_InterfacesCopy head branch name to clipboard